Interaction device, interaction method, and storage medium storing program

ABSTRACT

An interaction device include a processor. The processor being configured to acquire an alertness level of an occupant of a vehicle, request an utterance from the occupant in a case in which the acquired alertness level is below a threshold value, identify a rest point at which the vehicle can stop, measure a cycle spanning from initiation of an interaction until the alertness level falls below the threshold value again, and repeatedly request an utterance from the occupant at a regular interval that is shorter than the measured cycle during a time period from notifying the occupant that the rest point has been set as a destination of the vehicle to the vehicle arriving at the destination.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority under 35 USC 119 fromJapanese Patent Application No. 2020-127672 filed on Jul. 28, 2020, thedisclosure of which is incorporated by reference herein.

BACKGROUND Technical Field

The present disclosure relates to an interaction device, an interactionmethod, and a storage medium storing a program to rouse an occupant of avehicle.

Related Art

Japanese Patent Application Laid-Open (JP-A) No. 2015-162087 disclosesan in-vehicle system that restores a driver from a state of reducedalertness. When this in-vehicle system determines that the driver isunfocused or dozing, the in-vehicle system chooses and informs thedriver of a rest location at which the driver can rest. The in-vehiclesystem also executes a periodical operation to restore the driver fromtheir unfocused or dozing state until arriving at the chosen restlocation.

JP-A No. 2019-159711 discloses an alertness level maintaining devicethat helps to suppress fluctuations in an alertness level of a driverand maintain a relatively high alertness level. In this alertness levelmaintaining device, interaction with the driver is executed at randomintervals.

An operation to rouse the driver may be executed repeatedly in order toconvey the remaining time and distance to a rest point to the driver.However, in the in-vehicle system disclosed in JP-A No. 2015-162087,although the operation to rouse the driver is executed periodically, forsome drivers this operation may be executed after their alertness levelhas already dropped, and so there is room for improvement in thisrespect.

In the case of the alertness level maintaining device disclosed in JP-ANo. 2019-159711, the timing of the interaction is different on eachoccasion, and so it is difficult to convey the remaining time anddistance to the rest point.

SUMMARY

An object of the present disclosure is to provide an interaction device,an interaction method, and a storage medium storing a program thatconvey the remaining time and distance to a destination simply, and thatsecure a rousing effect regardless of differences between individualoccupants when executing an interaction repeatedly until reaching thedestination.

A first aspect is an interaction device including an acquisition sectionconfigured to acquire an alertness level of an occupant of a vehicle, arequest section configured to request an utterance from the occupant incases in which the alertness level acquired by the acquisition sectionis below a threshold value, a search section configured to identify arest point at which the vehicle can stop, and a measurement sectionconfigured to measure a cycle spanning from initiation of an interactionuntil the alertness level falls below the threshold value again. Therequest section is configured to repeatedly request an utterance fromthe occupant at a regular interval that is shorter than the measuredcycle during a time period from notifying the occupant that the restpoint has been set as a destination of the vehicle to the vehiclearriving at the destination.

In the interaction device of the first aspect, the acquisition sectionacquires the alertness level of the occupant, and then the requestsection compares this alertness level against the threshold value andrequests an utterance from the occupant in cases in which the alertnesslevel is below the threshold value. The search section of theinteraction device identifies a rest point at which the vehicle canstop, and notifies the occupant that this rest point has been set as thedestination of the vehicle. Moreover, the measurement section of theinteraction device measures an alertness level cycle spanning from theinitiation of interaction to when the alertness level falls below thethreshold value again, and the request section repeatedly requests anutterance at the regular interval that is shorter than the measuredcycle until the vehicle arrives at the destination.

According to this interaction device, by executing repeated interactionsuntil reaching the destination, the occupant is prompted to make a freshutterance before their falling alertness level reaches the thresholdvalue, based on the measured alertness level of the occupant. Thisenables a rousing effect to be secured, regardless of differencesbetween individual occupants. Moreover, prompting an utterance at theregular interval set based on the measured alertness level enables theremaining time and distance to the destination to be conveyed to theoccupant simply.

An interaction device of a second aspect is the interaction device ofthe first aspect, wherein the request section is configured to requestan utterance by prioritizing use of media content that effectivelyrouses the occupant from plural media content for rousing the occupant.

According to the interaction device of the second aspect, the rousingeffect can be enhanced compared to cases in which an utterance isrequested without consideration of whether or not the media contentrouses the occupant effectively.

An interaction device of a third aspect is the interaction device of thesecond aspect, further including a storage section that is configured tostore a degree of recovery of the alertness level together with themedia content used, wherein the request section is configured to requestan utterance by referencing the storage section so as to prioritize useof media content associated with a high degree of recovery.

In the interaction device of the third aspect, the media contentemployed for rousing of the occupant and the degree of recovery of thealertness level are stored together in the storage section, and therequest section prioritizes the use of media content associated with ahigh degree of recovery. This interaction device is thus capable ofusing media content chosen based on the past rousing effect with respectto the occupant, thereby enabling the rousing effect to be furtherenhanced.

An interaction device of a fourth aspect is the interaction device ofthe second aspect or the third aspect, wherein the request section isconfigured to vary the media content each time an utterance request isrepeated.

According to the interaction device of the fourth aspect, varying themedia content each time an utterance request is repeated enablesdesensitization resulting from using the same media content each time tobe suppressed.

The present disclosure is capable of conveying the remaining time anddistance to a destination simply, and of securing a rousing effectregardless of differences between individual occupants when executing aninteraction repeatedly until reaching the destination.

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the present disclosure will be described indetail based on the following figures, wherein:

FIG. 1 is a diagram illustrating a schematic configuration of an rousingsystem according to a first exemplary embodiment;

FIG. 2 is a block diagram illustrating a hardware configuration of avehicle of the first exemplary embodiment;

FIG. 3 is a block diagram illustrating a configuration of storage of thefirst exemplary embodiment;

FIG. 4 is a table illustrating contents of rousing efficacy level dataof the first exemplary embodiment;

FIG. 5A is a table illustrating contents of priority condition data ofthe first exemplary embodiment in an example in which usefulness is acondition;

FIG. 5B is a table illustrating contents of priority condition data ofthe first exemplary embodiment in an example in which a preference levelis a condition;

FIG. 6 is a block diagram illustrating a functional configuration of ahead unit of the first exemplary embodiment;

FIG. 7 is a flowchart illustrating a flow of alertness level detectionprocessing of the first exemplary embodiment;

FIG. 8 is a flowchart illustrating a flow of rousing processing of thefirst exemplary embodiment;

FIG. 9 is a flowchart illustrating a flow of rousing initiationprocessing of the first exemplary embodiment;

FIG. 10 is a flowchart illustrating a flow of rest proposal processingof the first exemplary embodiment;

FIG. 11 is a flowchart illustrating a flow of alertness maintenanceprocessing of the first exemplary embodiment; and

FIG. 12 is a flowchart illustrating a flow of arrival stage processingof the first exemplary embodiment.

DETAILED DESCRIPTION First Exemplary Embodiment

Configuration

As illustrated in FIG. 1 and FIG. 2 , a rousing system 10 of a firstexemplary embodiment is configured including a vehicle 12, an agentserver 14, and an information provision server 16. A head unit 20serving as an interaction device, a communication device 22, a globalpositioning system (GPS) device 23, a touch panel 24, a speaker 26, amicrophone 27, an alertness level detection system 28, and a camera 29are installed in the vehicle 12. The communication device 22 of thevehicle 12, the agent server 14, and the information provision server 16are connected to each other over a network N.

The agent server 14 includes functionality to provide agent-relatedservices, such as music streaming, information provision, and telephonecalls, for an occupant of the vehicle 12. The agent server 14 interpretsthe intent of an utterance by the occupant based on audio informationfrom the occupant acquired through the head unit 20, and providesinformation corresponding to the interpreted intent of the occupant tothe head unit 20.

The information provision server 16 includes functionality to providemedia content used when the agent is executed through the head unit 20.The information provision server 16 provides requested media content tothe head unit 20 based on a request from the head unit 20 or the agentserver 14.

As illustrated in FIG. 2 , the head unit 20 is configured including acentral processing unit (CPU) 20A, read only memory (ROM) 20B, randomaccess memory (RAM) 20C, storage 20D, a communication interface (I/F)20E, and an input/output I/F 20F. The CPU 20A, the ROM 20B, the RANI20C, the storage 20D, the communication I/F 20E, and the input/outputI/F 20F are connected together so as to be capable of communicating witheach other through an internal bus 20G.

The CPU 20A is a central processing unit that executes various programsand controls various sections. Namely, the CPU 20A reads a program fromthe ROM 20B or the storage 20D, and executes the program using the RAM20C as a workspace. The CPU 20A is an example of a processor.

The ROM 20B stores various programs and various data.

The RAM 20C acts as a workspace to temporarily store programs or data.

The storage 20D serves as a storage section and is configured by a harddisk drive (HDD) or a solid state drive (SSD) that stores variousprograms and various data. As illustrated in FIG. 3 , a processingprogram 100, rousing media content 110, setting information 120, rousingefficacy level data 130, and priority condition data 140 are stored inthe storage 20D of the present exemplary embodiment. Note that theprocessing program 100, the rousing media content 110, the settinginformation 120, the rousing efficacy level data 130, and the prioritycondition data 140 may be stored in the ROM 20B.

The processing program 100 is a program for controlling the head unit 20that serves as an interaction device.

Information such as song data, audio data, and text is stored as therousing media content 110 as media content for rousing the occupant.Note that the media content stored as the rousing media content 110 isnot necessarily stored as full data, and may be stored in the form of anaddress (i.e. a link) for an external server.

Setting contents such as permissions to actuate a rousing function andagent voices, as well as personal information such as the name of theoccupant using the rousing function, are stored in the settinginformation 120.

The efficacy of each type of media content in rousing the occupant isstored in the rousing efficacy level data 130. As illustrated in FIG. 4, the rousing efficacy stored in the rousing efficacy level data 130 isstored as a rousing efficacy level for respective types of mediacontent. The example in FIG. 4 illustrates rousing efficacy levels for agiven occupant. Specifically, of media content that may be provided whenthe rousing function has been actuated, news is set to a rousingefficacy level B, music is set to a rousing efficacy level A, audiobooksare set to a rousing efficacy level C, and hobby information is set to arousing efficacy level B. The rousing efficacy level A is the level thatrouses most effectively, and the rousing efficacy level decreases onprogression to B and C.

Predetermined conditions regarding which rest point to prioritize forprovision to the occupant in cases in which plural rest points,described later, have been selected are stored in the priority conditiondata 140. The predetermined conditions include the usefulness of theinformation to the occupant (Condition 1), preference levels of theoccupant (Condition 2), and frequency of past selection by the occupant(Condition 3). Note that any one out of Condition 1 to Condition 3 maybe applied singularly, or a combination of these conditions may beapplied. In cases in which a combination of these conditions is applied,the respective conditions may be weighted.

As illustrated in FIG. 5A, Condition 1, this being the usefulness of theinformation to the occupant, is stipulated for each of respectiveinformation types provided to the occupant. A provision section 264,described later, compares the calculated usefulness of each informationtype so as to prioritize suggesting to the occupant the rest point thatis the most useful, namely the best suited to them. In the example inFIG. 5A, the usefulness is set to 1.0 for “little congestion on way torest point”, 0.9 for “light traffic on way to rest point”, 0.7 for“eating facilities at rest point”, and 0.5 for “possible to refuel atrest point”. Note that the information such as “little congestion on wayto rest point”, “light traffic on way to rest point”, “eating facilitiesat rest point”, and “possible to refuel at rest point” is provided tothe occupant as useful information regarding the rest point.

As illustrated in FIG. 5B, Condition 2, this being the preference levelof the occupant, is stipulated for each of respective information typesprovided to the occupant. In cases in which there are plural comparableinformation types, the provision section 264, described later,references the preference levels to compare information types with ahigh preference level and decide which rest point to prioritize andsuggest to the occupant. In the example in FIG. 5B, for categories ofinformation that may be provided to the occupant, the preference levelis set to A for eating, C for shopping, B for ease of parking, and D forscenery. The preference level is set to A for the information that ismost preferable for the occupant, and the information becomes lesspreferable on progression through the preference levels B, C, and D.Note that information such as eating, shopping, ease of parking, andscenery is provided to the occupant as useful information regarding therest point.

Condition 3, this being the frequency of past selection by the occupant,includes not only the frequency with which a rest point itself has beenselected, but also the frequency with which similar rest points havebeen selected. Similar rest points refer to rest points having similarfacilities, for example service areas with a fast food restaurant, orservice areas with a dog run. The provision section 264, describedlater, compares the frequency of past selections in order to prioritizethe rest point with the highest selection frequency for suggestion tothe occupant.

As illustrated in FIG. 2 , the communication I/F 20E is an interface forconnecting with the communication device 22. For example, this interfaceemploys a CAN communication protocol. The communication I/F 20E isconnected to an external bus 20H.

The input/output I/F 20F is an interface for communicating with the GPSdevice 23, the touch panel 24, the speaker 26, the microphone 27, andthe alertness level detection system 28 installed in the vehicle 12.Note that the GPS device 23, the touch panel 24, the speaker 26, themicrophone 27, and the alertness level detection system 28 may bedirectly connected to the internal bus 20G Although the camera 29 of thepresent exemplary embodiment is directly connected to the alertnesslevel detection system 28, the camera 29 may be connected to thealertness level detection system 28 through the input/output I/F 20F.

The communication device 22 is a wireless communication module forcommunicating with the agent server 14 and the information provisionserver 16. This wireless communication module employs a communicationprotocol such as 5G, LTE, or Wi-Fi (registered trademark). Thecommunication device 22 is connected to the network N.

The GPS device 23 is a device that measures the current position of thevehicle 12. The GPS device 23 includes an antenna that receives signalsfrom GPS satellites.

The touch panel 24 is provided to an instrument panel or the like, andis a combination of a liquid crystal display serving as a displaysection and a touch pad serving as an input section.

The speaker 26 is provided to the instrument panel, a center console, afront pillar, a dashboard, or the like, and is a device for outputtingaudio provided by the agent.

The microphone 27 is provided to a front pillar, dashboard, or the likeof the vehicle 12, and is a device for picking up sounds uttered by theoccupant of the vehicle 12.

The alertness level detection system 28 includes functionality to detectan alertness level of the occupant. The alertness level detection system28 of the present exemplary embodiment detects the alertness level basedon images captured by the camera 29. Methods of detecting the alertnesslevel using a camera include a detection method based on eyeballmovement, a detection method based on blinking, a detection method basedon the pupils, and a detection method based on the facial expression ofthe occupant.

The camera 29 is provided to the instrument panel, an interior mirror,the front pillar, the dashboard, or the like, and is an imaging devicethat images the face of the occupant.

As illustrated in FIG. 6 , by executing the processing program 100, theCPU 20A of the head unit 20 of the present exemplary embodimentfunctions as an alertness level acquisition section 200, a preferenceacquisition section 210, a search section 220, a information-gatheringsection 225, a route guidance section 230, a measurement section 240, anintent interpretation section 250, and an utterance control section 260.The utterance control section 260 includes a request section 262 and theprovision section 264.

The alertness level acquisition section 200 serves as an acquisitionsection, and includes functionality to acquire the alertness level ofthe occupant of the vehicle 12. The alertness level acquisition section200 of the present exemplary embodiment acquires the alertness levelfrom the alertness level detection system 28. As previously described,the alertness level detection system 28 computes the alertness levelbased on images captured by the camera 29. Note that the alertness levelmay be detected and acquired in the head unit 20.

The preference acquisition section 210 includes functionality to acquirethe preferences of the occupant. The preference acquisition section 210of the present exemplary embodiment for example acquires a genre ofinformation preferred by the occupant through a mobile terminal or thelike in the possession of the occupant. The preference acquisitionsection 210 then reflects the acquired preferences of the occupant inthe preference levels in the priority condition data 140.

The search section 220 includes functionality to identify a rest pointat which the vehicle 12 can stop. Note that examples of rest pointsinclude parking areas, service areas, roadside cafes, conveniencestores, restaurants, and public bathing facilities. In cases in whichthe alertness level of the occupant falls below a threshold value whiletraveling in the vehicle 12, the search section 220 identifies one orplural rest points on the travel route at which the vehicle 12 can stop.

The information-gathering section 225 includes functionality to gatheruseful information that may be useful to the occupant regarding the restpoint identified by the search section 220. The information-gatheringsection 225 of the present exemplary embodiment acquires usefulinformation regarding the rest point from an external server such as theinformation provision server 16. In cases in which plural rest pointshave been identified, useful information regarding each of these restpoints is acquired.

The route guidance section 230 includes functionality to guide thevehicle 12 along a route to a destination set by the occupant. The routeguidance section 230 of the present exemplary embodiment is capable ofsetting the rest point identified by the search section 220 as thedestination and guiding the vehicle 12 to this destination. Note thatthis route guidance may be implemented by a car navigation systemconnected to the head unit 20.

The measurement section 240 includes functionality to measure analertness cycle, this being a cycle lasting until the alertness levelfalls below a threshold value. The measurement section 240 of thepresent exemplary embodiment measures the alertness cycle spanning frominitiation of an interaction during rousing initiation processing,described later, until the alertness level falls below the thresholdvalue again.

The intent interpretation section 250 includes functionality tointerpret the intent of an utterance by the occupant.

The utterance control section 260 serves as an utterance section, andincludes functionality to control utterances with which the agentaddresses the occupant. The utterance control section 260 provides audioinformation as information corresponding to the intent of the occupantas interpreted by the intent interpretation section 250. The utterancecontrol section 260 also provides media content when the rousingfunction is being executed.

In cases in which the alertness level acquired by the alertness levelacquisition section 200 is below the threshold value, the requestsection 262 provided at the utterance control section 260 requests anutterance from the occupant. Here, “requests an utterance” signifiesprompting the occupant to make an utterance. Such utterances may includehumming along to music, or singing a song.

Moreover, during alertness maintenance processing, described later,after the occupant has been notified that the destination of the vehicle12 has been set to the rest point, the request section 262 of thepresent exemplary embodiment repeatedly requests the occupant to make anutterance at a predetermined interval until the vehicle 12 arrives atthe destination. In the present exemplary embodiment, the “predeterminedinterval” refers to a playback cycle corresponding to an interval thatis shorter than the alertness cycle measured by the measurement section240.

Out of plural media contents for rousing the occupant, when requestingan utterance, the request section 262 prioritizes use of media contentthat rouses the occupant effectively. Specifically, the request section262 references the rousing efficacy level data 130 for the occupantusing the rousing function, and makes an utterance based on mediacontent corresponding to a media content type with a high rousingefficacy level.

The provision section 264 serves as a proposal section that provides theoccupant with the selected rest point and useful information regardingthe rest point in the form of audio information. For example, theprovision section 264 provides information such as the location of aservice area or parking area on an expressway being traveled on, thefacilities offered at this location, and the time until arrival at thislocation in the form of audio information. In cases in which plural restpoints have been identified by the search section 220, the provisionsection 264 provides information regarding the rest points in a sequencedetermined based on the conditions stipulated in the priority conditiondata 140.

Control Flow

Explanation follows regarding a flow of processing executed by the headunit 20 of the present exemplary embodiment, with reference to theflowcharts in FIG. 7 to FIG. 12 . The processing by the head unit 20 isimplemented by the CPU 20A functioning as the alertness levelacquisition section 200, the search section 220, the route guidancesection 230, the measurement section 240, the intent interpretationsection 250, and the utterance control section 260 described above.

First, explanation follows regarding the alertness level detectionprocessing in FIG. 7 .

At step S100 in FIG. 7 , the CPU 20A determines whether or not thealertness level has fallen below the threshold value. In cases in whichthe CPU 20A determines that the alertness level has fallen below thethreshold value (in cases in which step S100=Y), processing proceeds tostep S101. In cases in which the CPU 20A determines that the alertnesslevel has not fallen below the threshold value, namely, that thealertness level is the threshold value or greater (in cases in whichstep S100=N), the processing of step S100 is repeated.

At step S101, the CPU 20A detects that the alertness level has fallen.

At step S102, the CPU 20A determines whether or not the alertness levelhas reached the threshold value or greater. In cases in which the CPU20A determines that the alertness level has reached the threshold valueor greater (in cases in which step S102=Y), processing proceeds to stepS103. In cases in which the CPU 20A determines that the alertness levelhas not reached the threshold value or greater, namely that thealertness level is below the threshold value (in cases in which stepS102=N), the processing of step S102 is repeated.

At step S103, the CPU 20A performs a rousing efficacy evaluation.Namely, after executing media content or the like, the CPU 20A evaluatesthe efficacy of this media content in cases in which the alertness levelthat had fallen below the threshold value returns to the threshold valueor greater.

At step S104, the CPU 20A stores the rousing efficacy evaluation resultin the storage 20D.

At step S105, the CPU 20A determines whether or not the alertness levelhas fallen below the threshold value. In cases in which the CPU 20Adetermines that the alertness level has fallen below the threshold value(in cases in which step S105=Y), processing proceeds to step S106. Incases in which the CPU 20A determines that the alertness level has notfallen below the threshold value, namely, that the alertness level isthe threshold value or greater (in cases in which step S105=N), theprocessing of step S105 is repeated.

At step S106, the CPU 20A measures the alertness cycle. Specifically,the CPU 20A measures the duration between step S100 and step S105 as thealertness cycle.

At step S107, the CPU 20A stores the measured alertness cycle in thestorage 20D. The processing then returns to step S100.

Next, explanation follows regarding the rousing processing in FIG. 8 .

At step S200 in FIG. 8 , the CPU 20A executes initial settings.Specifically, the CPU 20A references the setting information 120 toacquire setting contents and personal information regarding the occupantusing the rousing function, and references the rousing efficacy leveldata 130 to acquire the rousing efficacy level for each media contenttype.

At step S201, the CPU 20A determines whether or not a fall in thealertness level has been detected. In cases in which the CPU 20Adetermines that a fall in the alertness level has been detected (incases in which step S201=Y), processing proceeds to step S202. In casesin which the CPU 20A determines that a fall in the alertness level hasnot been detected (in cases in which step S201=N), the processing ofstep S201 is repeated.

At step S202, the CPU 20A executes rousing initiation processing. Thiswill be described in detail later.

At step S203, the CPU 20A executes rest proposal processing. This willbe described in detail later.

At step S204, the CPU 20A determines whether or not the occupant hasagreed to take a rest. Specifically, the CPU 20A determines whether ornot the intent of an utterance of the occupant corresponds to agreementto take a rest. In cases in which the CPU 20A determines that theoccupant has agreed to take a rest (in cases in which step S204=Y),processing proceeds to step S205. In cases in which the CPU 20Adetermines that the occupant has not agreed to take a rest (in cases inwhich step S204=N), the rousing processing is ended.

At step S205, the CPU 20A executes alertness maintenance processing.This will be described in detail later.

At step S206, the CPU 20A executes arrival stage processing. This willbe described in detail later. The rousing processing is then ended.

Next, explanation follows regarding the rousing initiation processingillustrated in FIG. 9 .

At step S300 in FIG. 9 , the CPU 20A requests media content.Specifically, the CPU 20A references the rousing efficacy level data 130and loads media content with a high rousing efficacy level from therousing media content 110. In cases in which there is no suitable mediacontent in the rousing media content 110, media content is acquired fromthe information provision server 16.

At step S301, the CPU 20A determines whether or not media content hasbeen acquired. In cases in which the CPU 20A determines that mediacontent has been acquired (in cases in which step S301=Y), processingproceeds to step S302. In cases in which the CPU 20A determines thatmedia content has not been acquired (in cases in which step S301=N),processing returns to step S300.

At step S302, the CPU 20A notifies of the fall in the alertness level.Specifically, the CPU 20A may play music and output audio such as “Mr.Smith, you're looking sleepy” through the speaker 26. The occupant isthereby notified that their alertness level has fallen, accompanied bythe stimulus of the audible change provided by the music and calling oftheir name. In cases in which the vehicle 12 is being autonomouslydriven and the occupant is not driving, the reason and necessity ofaddressing the occupant may be explained, for example “Although thevehicle is being autonomously driven, you need to stay awake just incase”.

At step S303, the CPU 20A initiates an interaction with the occupant.Namely, the CPU 20A starts processing to receive utterances by theoccupant and interpret the intent of these utterances, and processing toprovide the occupant with information relating to the interpretedintent.

At step S304, the CPU 20A plays the media content and requests theoccupant to make an utterance. Specifically, the CPU 20A plays the mediacontent acquired in the processing of step S300, and prompts anutterance in response to this media content. For example, the CPU 20Amay play a song that the occupant knows and prompt the occupant to singalong at the start of the chorus. Alternatively, the CPU 20A may readfrom an audiobook and then prompt the occupant to repeat a read-outsentence.

At step S305, the CPU 20A determines whether or not the occupant hasmade an utterance. In cases in which the CPU 20A determines that theoccupant has made an utterance (in cases in which step S305=Y),processing proceeds to step S306. In cases in which the CPU 20Adetermines that the occupant has not made an utterance (in cases inwhich step S305=N), processing returns to step S304.

At step S306, the CPU 20A ends the interaction with the occupant. Therousing initiation processing is then ended.

Next, explanation follows regarding the rest proposal processing in FIG.10 .

At step S400 in FIG. 10 , the CPU 20A initiates an interaction with theoccupant. Namely, the CPU 20A starts processing to receive utterances bythe occupant, interpret the intent of these utterances, and provide theoccupant with information relating to the interpreted intent. Note thatthis processing relating to interaction may be continued uninterruptedfrom the interaction at step S306 described above.

At step S401, the CPU 20A selects available rest points. Specifically,the CPU 20A selects one or plural rest points at which the vehicle 12can stop on the travel route of the vehicle 12. For example, in cases inwhich the vehicle 12 is traveling along an expressway, the CPU 20A mayselect a parking area or a service area on the route as a rest point.

At step S402, the CPU 20A requests useful information regarding eachselected rest point from an external server such as the informationprovision server 16. For example, in cases in which a service area hasbeen selected as the rest point, congestion information from the currentlocation of the vehicle 12 to the service area, and informationregarding facilities such as toilets, kiosks, and restaurants at theservice area are requested from the information provision server 16.

At step S403, the CPU 20A determines whether or not the usefulinformation has been acquired. In cases in which the CPU 20A determinesthat the useful information has been acquired (in cases in which stepS403=Y), processing proceeds to step S404. In cases in which the CPU 20Adetermines that the useful information has not been acquired (in casesin which step S403=N), the processing of step S403 is repeated.

At step S404, the CPU 20A determines whether or not plural rest pointshave been selected. In cases in which the CPU 20A determines that pluralrest points have been selected (in cases in which step S404=Y),processing proceeds to step S405. In cases in which the CPU 20Adetermines that plural rest points have not been selected (in cases inwhich step S404=N), processing proceeds to step S406.

At step S405, the CPU 20A arranges the plural selected rest points in apriority sequence. Specifically, the CPU 20A references the prioritycondition data 140 to arrange the rest points in consideration of theCondition 1 to Condition 3 described previously.

At step S406, the CPU 20A proposes stopping off at the rest point andprovides the useful information. For example, after having explained theneed to take a rest, for example with “Taking a rest is the best way torelieve drowsiness”, the agent may further extol the merits of taking arest based on useful information regarding food or shopping, for example“The cake at Ebina service area is popular. Why don't you give it a try?It could be something to tell your friends about”. Lastly, the agent maymake a proposal to stop off at the rest point, for example with “Howabout stopping off at the service area?”. Note that in cases in whichplural rest points have been selected, the agent proposes the restpoints in the sequence in which they were arranged at step S405.

At step S407, the CPU 20A determines whether or not the occupant hasuttered a response to the proposal. In cases in which the CPU 20Adetermines that the occupant has uttered a response to the proposal (incases in which step S407=Y), processing proceeds to step S408. In casesin which the CPU 20A determines that the occupant has not uttered aresponse to the proposal (in cases in which step S407=N), the processingof step S407 is repeated.

At step S408, the CPU 20A determines whether or not the intent of theresponse could be interpreted. In cases in which the CPU 20A determinesthat the intent of the response could be interpreted (in cases in whichstep S408=Y), processing proceeds to step S409. In cases in which theCPU 20A determines that the intent of the response could not beinterpreted (in cases in which step S408=N), processing returns to stepS407.

At step S409, the CPU 20A ends the interaction with the occupant. Therest proposal processing is then ended.

Next, explanation follows regarding the alertness maintenance processingin FIG. 11 .

At step S500 in FIG. 11 , the CPU 20A acquires the alertness cyclestored at step S107.

At step S501, the CPU 20A sets the playback cycle. The playback cycle isset to a shorter duration than the alertness cycle. For example, theplayback cycle may be set to 70% to 90% of the duration of the alertnesscycle.

At step S502, the CPU 20A requests media content. Specifically, the CPU20A references the rousing efficacy level data 130 and loads the mediacontent with a high rousing efficacy level from the rousing mediacontent 110. In cases in which there is no suitable media content in therousing media content 110, media content is acquired from theinformation provision server 16. Note that the media content requestedat step S502 may be the same as the media content requested at stepS300, or may be different media content.

At step S503, the CPU 20A determines whether or not the media contenthas been acquired. In cases in which the CPU 20A determines that themedia content has been acquired (in cases in which step S503=Y),processing proceeds to step S504. In cases in which the CPU 20Adetermines that the media content has not been acquired (in cases inwhich step S503=N), processing returns to step S502.

At step S504, the CPU 20A initiates an interaction with the occupant.Namely, the CPU 20A starts processing to receive utterances by theoccupant, interpret the intent of these utterances, and provide theoccupant with information relating to the interpreted intent.

At step S505, the CPU 20A plays the media content, and requests theoccupant to make an utterance. Specifically, the CPU 20A plays the mediacontent acquired in the processing of step S502, and prompts anutterance in response to this media content. For example, the agent mayadvise of the distance to the rest point, for example with “You couldtake a rest 16 km ahead at Ebina service area”, and then promptutterances on plural occasions, such as “I'll play a song every 5minutes to keep you awake”. In cases in which the agent plays songs thatthe occupant knows, and prompts the occupant to sing along at the startof the chorus similarly to in the rousing initiation processing, theagent may also prompt the occupant to make an utterance by saying “Let'ssing along again. Not long now!”. In this example, the playback cycle isset to five minutes. A timer starts counting when an utterance isrequested.

At step S506, the CPU 20A determines whether or not the vehicle 12 hasarrived at the rest point. In cases in which the CPU 20A determines thatthe vehicle 12 has arrived at the rest point (in cases in which stepS506=Y), processing proceeds to step S508. In cases in which the CPU 20Adetermines that the vehicle 12 has not arrived at the rest point (incases in which step S506=N), processing proceeds to step S507.

At step S507, the CPU 20A determines whether or not the count value ofthe timer has reached or exceeded the playback cycle. In cases in whichthe CPU 20A determines that the count value of the timer has reached orexceeded the playback cycle (in cases in which step S507=Y), processingreturns to step S505. In cases in which the CPU 20A determines that thecount value of the timer has not yet reached or exceeded the playbackcycle, namely that the playback cycle has not yet elapsed (in cases inwhich step S507=N), processing returns to step S506.

At step S508, the CPU 20A ends the interaction with the occupant. Thealertness maintenance processing is then ended.

Next, explanation follows regarding the arrival stage processing in FIG.12 .

At step S600 in FIG. 12 , the CPU 20A initiates an interaction with theoccupant. Namely, the CPU 20A starts processing to receive utterances bythe occupant, interpret the intent of these utterances, and provide theoccupant with information relating to the interpreted intent. Note thatthis processing relating to interaction may be continued uninterruptedfrom the interaction at step S508 described above.

At step S601, the CPU 20A praises the occupant. Specifically, the CPU20A outputs audio through the speaker 26 to praise the occupant forhaving maintained alertness. For example, the agent may say “You'vereached Ebina service area. Well done. It's been a pleasure driving withyou. Take a well-deserved break and see you soon.”

At step S602, the CPU 20A ends the interaction with the occupant. Thearrival stage processing is then ended.

Summary of Exemplary Embodiment

In the head unit 20 of the first exemplary embodiment, the alertnesslevel acquisition section 200 acquires the alertness level of theoccupant, and then the request section 262 compares this alertness levelagainst the threshold value and requests the occupant to make anutterance in cases in which the alertness level is below the thresholdvalue. The search section 220 of the head unit 20 identifies a restpoint at which the vehicle 12 can stop, and notifies the occupant thatthis rest point has been set as the destination of the vehicle 12.Moreover, the measurement section 240 of the head unit 20 measures thealertness cycle spanning from the initiation of interaction to when thealertness level falls below the threshold value again, and the requestsection 262 repeatedly requests an utterance according to the playbackcycle that is shorter than the measured alertness cycle until thevehicle 12 arrives at the destination.

In the present exemplary embodiment, by executing repeated interactionsuntil reaching the destination, the occupant is prompted to make a freshutterance before their falling alertness level reaches the thresholdvalue, based on the measured alertness level of the occupant. Namely,since drowsiness comes in cycles, the media content is used to promptthe user to make an utterance before the drowsiness reaches its peak.Thus, the present exemplary embodiment enables a rousing effect to besecured, regardless of differences between individual occupants.Moreover, prompting the occupant to make an utterance at regularintervals set based on their measured alertness level conveys theremaining time and distance to the destination to the occupant simply.

In the present exemplary embodiment, when the request section 262requests the occupant to make an utterance, the request section 262references the rousing efficacy level data 130 when requesting anutterance such that when employing the rousing function, the use ofmedia content that rouses the occupant effectively is prioritized amongplural media content types. The present exemplary embodiment is therebycapable of enhancing a rousing effect compared to cases in which anutterance is requested without consideration of whether or not the mediacontent rouses the occupant effectively.

In the head unit 20 of the present exemplary embodiment, when the searchsection 220 identifies a rest point at which the vehicle 12 can stop,the information-gathering section 225 gathers useful informationregarding the rest point that may be useful to the occupant. Afterinteraction requesting the occupant to make an utterance has beeninitiated, the provision section 264 provides information regarding therest point and the useful information to the occupant in the form ofaudio. In the present exemplary embodiment, making the occupant awarethat their alertness level is low during an interaction and promptingthe occupant to rest in the course of the interaction enables a sense ofabruptness of the advice to rest or irritation at the rousing operationto be suppressed.

Second Exemplary Embodiment

A second exemplary embodiment differs from the first exemplaryembodiment in the method in which media content is used. Explanationfollows regarding points that differ from the first exemplaryembodiment. Note that other configuration is similar to that in thefirst exemplary embodiment, and so detailed explanation thereof isomitted.

Both the media content employed for the rousing function, and a degreeof alertness level recovery, are stored in the rousing media content 110in the storage 20D of the present exemplary embodiment (see step S104described previously). The request section 262 of the present exemplaryembodiment references the rousing media content 110 so as to prioritizeuse of media content associated with a high degree of recovery whenrequesting an utterance.

In addition to the advantageous effects of the first exemplaryembodiment, the present exemplary embodiment also exhibits the followingadvantageous effect. Namely, in the present exemplary embodiment, themedia content used is chosen based on the past rousing effect withrespect to the occupant, thereby enabling the rousing effect to befurther enhanced.

Third Exemplary Embodiment

A third exemplary embodiment differs from the first and second exemplaryembodiments in the method in which media content is used. Explanationfollows regarding points that differ from those in the first exemplaryembodiment. Note that other configuration is similar to that in thefirst exemplary embodiment, and so detailed explanation thereof isomitted.

The request section 262 of the present exemplary embodiment varies themedia content each time an utterance request is repeated. Namely, themedia content is varied each time the processing of step S505 of thealertness maintenance processing is executed.

In addition to the advantageous effects of the first exemplaryembodiment, the present exemplary embodiment also exhibits the followingadvantageous effect. Namely, in the present exemplary embodiment,varying the media content each time an utterance request is repeatedenables desensitization resulting from using the same media content eachtime to be suppressed.

REMARKS

Although the alertness level detection system 28 is configured by aseparate device to the head unit 20 in the above exemplary embodiments,there is no limitation thereto. An alertness level detection functionmay be incorporated into the head unit 20. Moreover, although the camera29 is employed to detect the alertness level in the above exemplaryembodiments, there is no limitation to this detection method. Forexample, a detection method in which heartrate is acquired from apressure sensor installed in a seat, a detection method based on asteering angle of a steering wheel, or a detection method based on atravel position of the vehicle 12 in a traffic lane may be adopted.

Note that the various processing executed by the CPU 20A reading andexecuting software (a program) in the above exemplary embodiments may beexecuted by various types of processor other than a CPU. Such processorsinclude programmable logic devices (PLD) that allow circuitconfiguration to be modified post-manufacture, such as afield-programmable gate array (FPGA), and dedicated electric circuits,these being processors including a circuit configuration custom-designedto execute specific processing, such as an application specificintegrated circuit (ASIC). The processing may be executed by any one ofthese various types of processor, or by a combination of two or more ofthe same type or different types of processor (such as plural FPGAs, ora combination of a CPU and an FPGA). The hardware structure of thesevarious types of processors is more specifically an electric circuitcombining circuit elements such as semiconductor elements.

In the above exemplary embodiments, the various programs are in a formatpre-stored (installed) in a computer-readable non-transitory storagemedium. For example, the processing program 100 of the head unit 20 ispre-stored in the storage 20D. However, there is no limitation thereto,and the program may be provided in a format recorded on a non-transitorystorage medium such as compact disc read only memory (CD-ROM), digitalversatile disc read only memory (DVD-ROM), or universal serial bus (USB)memory. Alternatively, the program may be provided in a formatdownloadable from an external device through a network.

The flow of processing explained in the above exemplary embodiments ismerely an example, and superfluous steps may be omitted, new steps maybe added, or the processing sequence may be changed within a range notdeparting from the spirit of the present disclosure.

What is claimed is:
 1. An interaction device, comprising: a processorcircuit configured to: acquire, via a sensor provided on a vehicle, astate of an occupant of the vehicle and calculate an alertness level ofthe occupant based on the acquired state of the occupant; via a speakerprovided on the vehicle, output audio information to the occupant thatrequests an utterance from the occupant in a case in which thecalculated alertness level is below a threshold value; determine whetheror not the occupant responds, via a microphone, to the request for anutterance; determine whether or not the alertness level has recovered tothe threshold value or greater as a result of requesting the utterancefrom the occupant; identify a rest point at which the vehicle can stopand notify the occupant via the speaker that the rest point has been setas a destination of the vehicle; calculate a cycle spanning from a timethe alertness level was determined to have recovered to the thresholdvalue or greater as a result of requesting the utterance from theoccupant until the alertness level falls below the threshold valueagain; and repeatedly output audio information that requests utterancesfrom the occupant at a regular interval that is shorter than thecalculated cycle during a time period from notifying the occupant thatthe rest point has been set as a destination of the vehicle to thevehicle arriving at the destination.
 2. The interaction device of claim1, wherein the processor circuit is configured to request the utteranceby prioritizing use of media content that effectively rouses theoccupant from a plurality of media content for rousing the occupant. 3.The interaction device of claim 2, further comprising a storage circuit,wherein: the processor circuit is configured to store a degree ofrecovery of the alertness level in the storage section together with themedia content used; and the processor circuit is configured to requestthe utterance by referencing the storage section so as to prioritize useof media content associated with a high degree of recovery.
 4. Theinteraction device of claim 2, wherein the processor circuit isconfigured to vary the media content each time an utterance request isrepeated.
 5. The interaction device of claim 1, wherein the processorcircuit is configured to propose a plurality of the identified restpoints to the occupant in a priority sequence based on one or moreconditions in a case in which the processor circuit has identified aplurality of the rest points.
 6. The interaction device of claim 5,wherein the processor circuit is configured to set the priority sequenceby applying a degree of usefulness of the identified rest points to theoccupant as one of the one or more conditions.
 7. The interaction deviceof claim 5, wherein the processor circuit is configured to set thepriority sequence by applying a preference level of the occupantregarding the identified rest points as one of the one or moreconditions.
 8. The interaction device of claim 5, wherein the processorcircuit is configured to set the priority sequence by applying a pastselection frequency by the occupant of the identified rest points as oneof the one or more conditions.
 9. The interaction device of claim 5,wherein the processor circuit is configured to set the priority sequenceof the plurality of rest points by applying a weighting to each of aplurality of the conditions.
 10. The interaction device of claim 5,wherein the processor circuit is configured to propose the rest point tothe occupant together with information that is useful to the occupant.11. The interaction device of claim 1, wherein, in a case in which thedestination has been reached after requesting the utterance from theoccupant, the processor circuit is configured to make an utterancepraising the occupant on arrival at the destination.
 12. An interactionmethod in which a computer executes a process comprising: acquiring, viaa sensor provided on a vehicle, a state of an occupant of the vehicleand calculating an alertness level of the occupant based on the acquiredstate of the occupant; via a speaker provided on the vehicle, outputtingaudio information to the occupant that requests an utterance from theoccupant in a case in which the calculated alertness level is below athreshold value; determining whether or not the occupant responds, via amicrophone, to the request for an utterance; determining whether or notthe alertness level has recovered to the threshold value or greater as aresult of requesting the utterance from the occupant; identifying a restpoint at which the vehicle can stop and notifying the occupant via thespeaker that the rest point has been set as a destination of thevehicle; calculating a cycle spanning from a time the alertness levelwas determined to have recovered to the threshold value or greater as aresult of requesting the utterance from the occupant until the alertnesslevel falls below the threshold value again; and repeatedly outputtinginformation that requests utterances from the occupant at a regularinterval that is shorter than the calculated cycle during a time periodfrom notifying the occupant that the rest point has been set as adestination of the vehicle to the vehicle arriving at the destination.13. A non-transitory storage medium storing a program executable by acomputer to perform a process comprising: acquiring, via a sensorprovided on a vehicle, a state of an occupant of the vehicle andcalculating an alertness level of the occupant based on the acquiredstate of the occupant; via a speaker provided on the vehicle, outputtingaudio information to the occupant that requests an utterance from theoccupant in a case in which the calculated alertness level is below athreshold value; determining whether or not the occupant responds, via amicrophone, to the request for an utterance; determining whether or notthe alertness level has recovered to the threshold value or greater as aresult of requesting the utterance from the occupant; identifying a restpoint at which the vehicle can stop and notifying the occupant via thespeaker that the rest point has been set as a destination of thevehicle; calculating a cycle spanning from a time the alertness levelwas determined to have recovered to the threshold value or greater as aresult of requesting the utterance from the occupant until the alertnesslevel falls below the threshold value again; and repeatedly outputtinginformation that requests utterances from the occupant at a regularinterval that is shorter than the calculated cycle during a time periodfrom notifying the occupant that the rest point has been set as adestination of the vehicle to the vehicle arriving at the destination.